Automatic plumb-bob



E. S. BUSH.

AUTOMATIC PLUMB BOB.

APPLICATION FILED'SEPT. 19. 1919.

Patented Nov. 2, 1920.

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AUTOMATIC PLUMB BOB.

APPLICATION FILED SEPT. 19, 1919.

1,357,270; Patented Nov. 2,1920.

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EUGENE STANLEY BUSH, OF PENDLETON, OREGON.

AUTOMATIC PLUMB-BOB.

Specification of Letters Patent.

Patented N on. 2, 1920;

Application filed September 19, 1919. Serial No. 324,744.

To all whom. it may concern:

Be it known that I, EUGENE STANLEY BUsr-i, a citizen of the United States,and a resident of Pendleton, in the county of Umatilla and State of Oregon, have invented certain new and useful Improvements in .rilltOillfltlC Plumb-Bobs, oi which the following is a specification.

My invention is an improvement in automatic plumb bobs, and the ini'ention hastor its objectto provide a bob wherein the supporting cord is connected to the weight in such manner that when not in use the cord may be automatically wound. up within the bob, and wherein any length of cord may be withdrawn and the bob clamped to the cord to restrain the operation of the winding up means until it is desired to release the same.

In the drawings:

Figure 1 is a vertical section of the improved bob;

Fig. 2 is an end view of the cord controlling mechanism;

Fig. 3 is a vertical section in the plane of the axis of the reel;

Fig. 4: is a top plan view;

Fig. 5 is a bottom plan view.

In the present embodiment of the invention the improved bob, which is of the usual shape and of any suitable material, is chambered at its upper or large end, and the bob preferably consists of a lower section 1, and upper section 2 and a plug 3 for closing the top of the upper section.

The lower section has an externally threaded nipple 4 which engages with an internally threaded rabbet in the upper section 2 to tightly connect the sections, and the plug has a reduced nipple which is threaded within an opening in the upper section 2.

The sections 1 and 2 are chambered, as indicated at 6, the chamber being circular in cross section and adapted to receive the wind- .ing up mechanism for the cord, and the plug 3 has an axial opening 7 through which the cord, indicated at 8, may extend.

The winding up mechanism comprises a support in the form of a disk 9 having series of depending bracket arms 10, the arms 10 being at the edges of the disk while the arms 16 are on opposite sides of the center and spaced inwardly from the arms 10, the

four arms being in register. Each arm, as shown, has an angular extension at its upper end which is riveted or otherwise secured to the plate 9.

A shaft'll is journaled in the arms 10 and 10, the ends of the shaft being reduced to engage reduced openings in the arms 10, and a reel 12 is secured to the shaft between the arms 10 Upon this reel the lower end of the cord 8 is adapted to wind, the said lower end being secured to thereel in any suitable or desired manner.

From the reel the cord passes through a radial slot 13 in the disk 9, and through a brake to be presently described, to a suitable support for supporting the bob, as, for instance, a theodolite or other instrument. This shaft 11 also carries pinions 14 between the arms 10 and 10 and these pinions mesh with teeth 15 on casings 16 which are journaled on shafts 17, held in the arms 10 and 1O at each side of the reel, and a coil spring 18 is arranged in each case.

Each of these springs is connected with the casing and with the shaft in a manner to cause the casings to rotate in a direction to wind up the cord on the reel. Brake mechanism is provided for engaging the cord to hold from winding so that any desired length may be withdrawn from-the reel to support the bob at any desired distance below the point of attachment of the free end of the cord.

The said brake mechanism comprises a pair of angle plates 19, each of which consists of two portions extending at an acute angle with respect to each other. One of the portions of each angle plate is securely riveted to the plate 9 and the other portion extends upwardly and toward the corresponding portion o'l the other angle plate. Each of the said portions is provided at its free end with a brake shoe 20 and these shoes are spaced apart slightly from each other as shown.

The plug 3 is reamed or counterbored as indicated at 21 at its inner end, and the brake shoes 20 extend up into this reamed or counterbored portion when the plug is turned home, as shown in Fig. 1. When the plug is so turned the brake shoes are compressed upon the cord to firmly'clamp thesame to the plumb bob so that the reel cannot wind up the same. To release the cord it is only necessary to slightly turn the plug 3 to release the pressure of the brake shoes on the cord. The springs always act normally to operate the reel to Wind up the cord.

In practice, when the bob is not in use, the plug 8 is loosened and the cord is permitted to Wind up upon the reel. T he bob may be laid away in this condition and when it is desired to use the same the plug is again loosened, a. sufficient length of cord is drawn out, and the plug is then turned to secure the cord.

The bob may now be used in the usual manner, and When through using a slight loosening of the plug Will permit the reel to Wind up the cord. Referring to Fig. 1, it will be seen that the support 9 is secured to the section 2 of the bob, so that When this section is removed the reel and its controlling mechanism is also removed.

I claim:

In combination a plumb bob having a chamber, a reel journaled in the chamber and having one end of a supporting cord for the hub secured thereto, normally operative means for turning the reel in a direction to Wind up the cord, and manually controlled means for clamping the cord to brake the movement thereof from the chamber, said means comprising angle brackets each consisting of a portion fixed Within the chamber and a portion inclining oiitwardly away therefrom and having a brake shoe at its free end, the shoes of the angle plates cooperating to grasp the cord between them, said bob having an opening for the cord, and a plug through which the cord passes and threaded into the opening and engaging the inclined portions of the angle plates at its inner end.

EUGENE STANL tr BUSH. 

